// script.aculo.us slider.js v1.6.5, Wed Nov 08 14:17:49 CET 2006

// Copyright (c) 2005, 2006 Marty Haught, Thomas Fuchs 
//
// script.aculo.us is freely distributable under the terms of an MIT-style license.
// For details, see the script.aculo.us web site: http://script.aculo.us/

if (!Control)
	var Control = {};
Control.Slider = Class.create();

// options:
//  axis: 'vertical', or 'horizontal' (default)
//
// callbacks:
//  onChange(value)
//  onSlide(value)
Control.Slider.prototype = {
	initialize : function(handle, track, options) {
		var slider = this;

		if (handle instanceof Array) {
			this.handles = handle.collect(function(e) {
				return $(e)
			});
		} else {
			this.handles = [ $(handle) ];
		}

		this.track = $(track);
		this.options = options || {};

		this.axis = this.options.axis || 'horizontal';
		this.increment = this.options.increment || 1;
		this.step = parseInt(this.options.step || '1');
		this.range = this.options.range || $R(0, 1);

		this.value = 0; // assure backwards compat
		this.values = this.handles.map(function() {
			return 0
		});
		this.spans = this.options.spans ? this.options.spans.map(function(s) {
			return $(s)
		}) : false;
		this.options.startSpan = $(this.options.startSpan || null);
		this.options.endSpan = $(this.options.endSpan || null);

		this.restricted = this.options.restricted || false;

		this.maximum = this.options.maximum || this.range.end;
		this.minimum = this.options.minimum || this.range.start;

		// Will be used to align the handle onto the track, if necessary
		this.alignX = parseInt(this.options.alignX || '0');
		this.alignY = parseInt(this.options.alignY || '0');

		this.trackLength = this.maximumOffset() - this.minimumOffset();

		this.handleLength = this.isVertical() ? (this.handles[0].offsetHeight != 0 ? this.handles[0].offsetHeight
				: this.handles[0].style.height.replace(/px$/, ""))
				: (this.handles[0].offsetWidth != 0 ? this.handles[0].offsetWidth
						: this.handles[0].style.width.replace(/px$/, ""));

		this.active = false;
		this.dragging = false;
		this.disabled = false;

		if (this.options.disabled)
			this.setDisabled();

		// Allowed values array
		this.allowedValues = this.options.values ? this.options.values
				.sortBy(Prototype.K) : false;
		if (this.allowedValues) {
			this.minimum = this.allowedValues.min();
			this.maximum = this.allowedValues.max();
		}

		this.eventMouseDown = this.startDrag.bindAsEventListener(this);
		this.eventMouseUp = this.endDrag.bindAsEventListener(this);
		this.eventMouseMove = this.update.bindAsEventListener(this);

		// Initialize handles in reverse (make sure first handle is active)
		this.handles
				.each(function(h, i) {
					i = slider.handles.length - 1 - i;
					slider
							.setValue(
									parseFloat((slider.options.sliderValue instanceof Array ? slider.options.sliderValue[i]
											: slider.options.sliderValue)
											|| slider.range.start), i);
					Element.makePositioned(h); // fix IE
					Event.observe(h, "mousedown", slider.eventMouseDown);
				});

		Event.observe(this.track, "mousedown", this.eventMouseDown);
		Event.observe(document, "mouseup", this.eventMouseUp);
		Event.observe(document, "mousemove", this.eventMouseMove);

		this.initialized = true;
	},
	dispose : function() {
		var slider = this;
		Event.stopObserving(this.track, "mousedown", this.eventMouseDown);
		Event.stopObserving(document, "mouseup", this.eventMouseUp);
		Event.stopObserving(document, "mousemove", this.eventMouseMove);
		this.handles.each(function(h) {
			Event.stopObserving(h, "mousedown", slider.eventMouseDown);
		});
	},
	setDisabled : function() {
		this.disabled = true;
	},
	setEnabled : function() {
		this.disabled = false;
	},
	getNearestValue : function(value) {
		if (this.allowedValues) {
			if (value >= this.allowedValues.max())
				return (this.allowedValues.max());
			if (value <= this.allowedValues.min())
				return (this.allowedValues.min());

			var offset = Math.abs(this.allowedValues[0] - value);
			var newValue = this.allowedValues[0];
			this.allowedValues.each(function(v) {
				var currentOffset = Math.abs(v - value);
				if (currentOffset <= offset) {
					newValue = v;
					offset = currentOffset;
				}
			});
			return newValue;
		}
		if (value > this.range.end)
			return this.range.end;
		if (value < this.range.start)
			return this.range.start;
		return value;
	},
	setValue : function(sliderValue, handleIdx) {
		if (!this.active) {
			this.activeHandleIdx = handleIdx || 0;
			this.activeHandle = this.handles[this.activeHandleIdx];
			this.updateStyles();
		}
		handleIdx = handleIdx || this.activeHandleIdx || 0;
		if (this.initialized && this.restricted) {
			if ((handleIdx > 0) && (sliderValue < this.values[handleIdx - 1]))
				sliderValue = this.values[handleIdx - 1];
			if ((handleIdx < (this.handles.length - 1))
					&& (sliderValue > this.values[handleIdx + 1]))
				sliderValue = this.values[handleIdx + 1];
		}
		sliderValue = this.getNearestValue(sliderValue);
		this.values[handleIdx] = sliderValue;
		this.value = this.values[0]; // assure backwards compat

		this.handles[handleIdx].style[this.isVertical() ? 'top' : 'left'] = this
				.translateToPx(sliderValue);

		this.drawSpans();
		if (!this.dragging || !this.event)
			this.updateFinished();
	},
	setValueBy : function(delta, handleIdx) {
		this.setValue(this.values[handleIdx || this.activeHandleIdx || 0]
				+ delta, handleIdx || this.activeHandleIdx || 0);
	},
	translateToPx : function(value) {
		return Math
				.round(((this.trackLength - this.handleLength) / (this.range.end - this.range.start))
						* (value - this.range.start))
				+ "px";
	},
	translateToValue : function(offset) {
		return ((offset / (this.trackLength - this.handleLength) * (this.range.end - this.range.start)) + this.range.start);
	},
	getRange : function(range) {
		var v = this.values.sortBy(Prototype.K);
		range = range || 0;
		return $R(v[range], v[range + 1]);
	},
	minimumOffset : function() {
		return (this.isVertical() ? this.alignY : this.alignX);
	},
	maximumOffset : function() {
		return (this.isVertical() ? (this.track.offsetHeight != 0 ? this.track.offsetHeight
				: this.track.style.height.replace(/px$/, ""))
				- this.alignY
				: (this.track.offsetWidth != 0 ? this.track.offsetWidth
						: this.track.style.width.replace(/px$/, ""))
						- this.alignY);
	},
	isVertical : function() {
		return (this.axis == 'vertical');
	},
	drawSpans : function() {
		var slider = this;
		if (this.spans)
			$R(0, this.spans.length - 1).each(function(r) {
				slider.setSpan(slider.spans[r], slider.getRange(r))
			});
		if (this.options.startSpan)
			this.setSpan(this.options.startSpan, $R(0,
					this.values.length > 1 ? this.getRange(0).min()
							: this.value));
		if (this.options.endSpan)
			this.setSpan(this.options.endSpan, $R(this.values.length > 1 ? this
					.getRange(this.spans.length - 1).max() : this.value,
					this.maximum));
	},
	setSpan : function(span, range) {
		if (this.isVertical()) {
			span.style.top = this.translateToPx(range.start);
			span.style.height = this.translateToPx(range.end - range.start
					+ this.range.start);
		} else {
			span.style.left = this.translateToPx(range.start);
			span.style.width = this.translateToPx(range.end - range.start
					+ this.range.start);
		}
	},
	updateStyles : function() {
		this.handles.each(function(h) {
			Element.removeClassName(h, 'selected')
		});
		Element.addClassName(this.activeHandle, 'selected');
	},
	startDrag : function(event) {
		if (Event.isLeftClick(event)) {
			if (!this.disabled) {
				this.active = true;

				var handle = Event.element(event);
				var pointer = [ Event.pointerX(event), Event.pointerY(event) ];
				var track = handle;
				if (track == this.track) {
					var offsets = Position.cumulativeOffset(this.track);
					this.event = event;
					this.setValue(this
							.translateToValue((this.isVertical() ? pointer[1]
									- offsets[1] : pointer[0] - offsets[0])
									- (this.handleLength / 2)));
					var offsets = Position.cumulativeOffset(this.activeHandle);
					this.offsetX = (pointer[0] - offsets[0]);
					this.offsetY = (pointer[1] - offsets[1]);
				} else {
					// find the handle (prevents issues with Safari)
					while ((this.handles.indexOf(handle) == -1)
							&& handle.parentNode)
						handle = handle.parentNode;

					if (this.handles.indexOf(handle) != -1) {
						this.activeHandle = handle;
						this.activeHandleIdx = this.handles
								.indexOf(this.activeHandle);
						this.updateStyles();

						var offsets = Position
								.cumulativeOffset(this.activeHandle);
						this.offsetX = (pointer[0] - offsets[0]);
						this.offsetY = (pointer[1] - offsets[1]);
					}
				}
			}
			Event.stop(event);
		}
	},
	update : function(event) {
		if (this.active) {
			if (!this.dragging)
				this.dragging = true;
			this.draw(event);
			// fix AppleWebKit rendering
			if (navigator.appVersion.indexOf('AppleWebKit') > 0)
				window.scrollBy(0, 0);
			Event.stop(event);
		}
	},
	draw : function(event) {
		var pointer = [ Event.pointerX(event), Event.pointerY(event) ];
		var offsets = Position.cumulativeOffset(this.track);
		pointer[0] -= this.offsetX + offsets[0];
		pointer[1] -= this.offsetY + offsets[1];
		this.event = event;
		this.setValue(this.translateToValue(this.isVertical() ? pointer[1]
				: pointer[0]));
		if (this.initialized && this.options.onSlide)
			this.options.onSlide(this.values.length > 1 ? this.values
					: this.value, this);
	},
	endDrag : function(event) {
		if (this.active && this.dragging) {
			this.finishDrag(event, true);
			Event.stop(event);
		}
		this.active = false;
		this.dragging = false;
	},
	finishDrag : function(event, success) {
		this.active = false;
		this.dragging = false;
		this.updateFinished();
	},
	updateFinished : function() {
		if (this.initialized && this.options.onChange)
			this.options.onChange(this.values.length > 1 ? this.values
					: this.value, this);
		this.event = null;
	}
}